Making little holes in mesh
You could fake holes with normal or bump maps, but if you want to create real holes, create a plane, subdivide, select all except the borders:

Press CtrlB to bevel the vertices (go into the Operator box to select Vertices):

If you want more than 4 vertex holes, increase the amount of Segments and choose Shape &gt; 1 to make them round:

In Face Selection mode, select one face and press ShiftG &gt; Polygon Sides to select all the similar faces:

If you ever change the holes size, choose Transform Pivot Point &gt; Individual Origins. When you're good, press i twice to inset each face:

Extrude down a little bit, then again twice, then give it a Subdivision Surface and Shade Smooth: